The present invention relates to panty briefs formed by a flat knitted, substantially rectangular front piece and back piece, which are made separately, and which by interknitting are connected along marginal edge zones in the sides of the panty briefs for forming side seams, and along a part of the bottom of the panty briefs for forming a crotch region separating two non-connected parts of the marginal edge zones at the bottom of the panty briefs for forming leg openings, the panty briefs being made with elastic threads, which generally extend from one side to the other of the front and back pieces for providing a circumferentially elastic contraction in the panty briefs.